If you want to live in Singapore, you need to have a job offer. Every major IT company (and many minors) has an Asian/SE Asian HQ there and they're constantly hiring.

Winging it on your own is considerably more complicated, but feasible if you're well paid and keen to start your own business, just look up EntrePass.

Getting into SG? What do you mean?

You want to come as a tourist or..? I just completed my first year here in SG, maybe I can answer specific questions?